Road-roller.



1. H. HENDERSON.

ROAD ROLLER.

v APPLICA 9,1915.

l 909257 Patentedeuly 4, 1916.

I 7 v I g v L i l 1 z 217/ l L /i 0 /7 Q EL-W E 111 M1@ Q WJTNESSES: 4f; 6 7 INVENTOR.

JOHN H. HENDERSON, OF OAKLAND, CALIFORNIA.

ROAD-ROLLER.

specificati ers Patent.' l Patented July, 1916.

Application led I une 29, 1915. Serial N o. 37,027.

T 0 all whom t 'may concern:

Be it known that I, JOHN H. HENDERSON, a citizen of the United States, and resident of Oakland, in the county of Alameda' and State of California, have invented new and useful Improvements in RoadRollers, of which the following is a. specification.

Heretofore in the construction of roads, it has been customary to tamp or roll the surface during the process of building the road, and also upon its nal completion by a roller or other device, which applies substantially a constant pressure over a smooth surface, with the result that, where there are any inequalities in the support of said surface, the roller riding upon the supported surface, fails to depress, detect or disclose the lack of support over any given small area. The failure to discover improperly supported areas results in theroad being completed with weak spots which later under trafiicon the surface develop into cavities disastrous to the road surface. The cutting out and repairing of these cavities after the road is finished, in an effort to build them up to the proper surface, is a laborious and expensive process and extremely inconvenient and costly to tra-Hic.

In my road roller, l provide a series of weighted members which cause Van equal pressure over each and every .section of the road during the rolling process, thus causing depressions in any areas or spots which may be improperly or insufficiently-supported. These depressions are occasioned by the application of unit pressures over every part of the road surface, and by causing every portion of the road surface .t0 be subjected to the `maximum test, or rolling pressure. Depressions will .therefore initially occur during the rolling process with my roller if at any point the foundation is defective or inadequate to support this maximum test pressure. After my roller has passed over the surface, such depressions are at once observable and are thenproperly filled during the initial road making, thus providing a road bed of equal supporting qualities at every oint and avoiding disastrous results hereto ore experienced.

The accompanying figures illustrate a preferred form of my road roller, and referring to these in which similar letters refer to similar parts z-Figure 1 shows a perspective view of the road roller arranged to be drawn by horses or suitable power tractor,

Fig. 2 illustrates in detail one of the weighted members of the roller battery and partlcularly its arrangement and mounting upon the shaft. Fig. 3 shows in cross section an assembly of the battery of rollers passing,

over a road bed and the action of the weighted members upon a weak spot in said road bed. Fig. 4 shows in side section, the depresslon occasioned in the road bed by the weighted members as they are leaving the said depression and rolling out upon the normal hardsurface of the road bed. Fig. 5 shows in detail one form of clearance spaces that it is advisable to leave between the weighted members so as to facilitate their clearing themselves and preventing their becoming inoperative through the wedging of rocks, dirt, etc. Fig. 6 shows the arrangement by which the weighted members may be locked in a central position with respect to each other and by which the weight or pressure acting upon the contact surface under each member may be varied. Fig. 7 shows in part, a section through the axis of Fig. 6 and one of the endrolls or wheels and the manner of adjusting the xle for varying the pressure of the memers.

Inthe figures (a) is a frame work by which the roller is moved over the road surface, and while I have shown this to be drawn by horses it is obvious that -any well known form of tractor may be employed or the roller may be built in the frame with a suitable gasolene or steam engine or other :motive power for driving it. The two sides of 4this frame are bridged by the axle (b) upon which is mounted the rolls or wheels (c) (c) and spaced between (c) and (0') over thesa-id axle are the weighted members (d) (c) (d) and (lim). These I prefer to make of disk form, as for example, of heavy cast iron, having a concentric hole (e) through their centers, and Awith their circumferences of such width as to make the roller surface whenthe weighted members are all in their normal positions substantially cylindrical. The inner faces of the rolls are relieved, forming the space (f) (Fig. 5) and are turned so that their outer edges just clear each other at (g). An alternate axle base (Z1) such that by raising the rectangular hollow axle the spring (j) is coin-.-

pressed, forcing the roller against the inner surface (e) of the member (d) thus reducing the eii'ective weightV upon the road surface (Z) by an amount equivalent to the compression of the said spring. Y

vAs the rectangular hollow axle (05') is raised, the roller bearings (h) (L) are forced outwardly until they finally engage with the interior surface of the concentric hole (e), atwhich time, the spring (j) is compressed to a degree suflicientv to support the weight of the roll (Z) in its central o1- normal position. These roller bearings (la.) (L) are mounted on a system of pivots and levers in the well kr `)wn form of a pantograph, the axis of the roller (i) sliding in suitable grooves (c), that is, it may at all times move vertically, but is prevented from horizontal displacement. If the hollow rectangular axle `is dropped such that the spring (j) expands, thus permitting the welghted member to exert a greater force upon the contact line with'thel roadway (Z),A

the roller bearings (1I) (h) (zf) are drawn inwardly to their dotted position (27) (z,)

' (L), thus giving clearance between them and the surface (e) so that the roll will upon meeting a wea-k spot -in the roadway (Z) be permitted to descend with respect to the axle (a). In other words, the rollers (i) (l1.) (L) will, when the rectangular hollow axle is in its elevated position, form a lock for the interior surface (e) constraining it to move concentrically with the center of the axle (af). It is to be understood that in using this adjusting and locking de vice that a similar set of parts is to be assembled within each of the elements (d) (di) (dl/l). i

By raising the axle (a) to a suiiiclent degree, the pressure of the member (eZ) upon the road (Z) may be made as light as required or vby depressing the axle (a) the Y. spring compression is reduced and a greater pressure will then be exerted by the ro1l'(Z) upon the surface (Z). The axle (a) is raised or lowered from the two ends by any suitable means, one of which is indicated in Fig. 7 vin which the axle carries the threaded block slidin endwise within the sleeve bearing (n), an through whicht'hreaded l( lock (m), extends the threaded cranklever 0 a (al by the handle (0'), the threaded block (m), and with it, the axle (a) is raised, thus -relievin the pressure .of the member (dm) uponte surface (Z). Any member or all of the members may be provided with such springs. The sleeve bearing (n) is rigidly connected to the frame (a).

The action of my roller is as follows Upon being drawn over the surface oa roadway (Z)V the weighted members comvsuchthat by rotating the crank lever press the surface to a degree proportional to their effective weight upon the line of support, which may be made suitable to the material being employed in the road, by adjusting the axle (a) by the cranks as (o) (0*) at each end of the axle' (a). During the rolling process, if any portion of the road being'rolled is unable to resist the pressure of the weighted member immediately above it, a depression will be occasioned as at (Z), 1" igs. 3 and 4, the members immediately over such weak spot in the roadway being allowedto move freely downward because of the clearance of the hole (e) about the "be beveled or cham'fered to suit individual conditions. Thev means shown in Figs. 6 and 90 7 is one form of my device for independently? adjusting and locking the members with respect to each other in a central position, and it is obvious that other means of locking thesetogether and with the side wheels (c) (c) may be employed, as'for example, aseries of holes (q) (q) (g) may be employed thrcngh which bars or rods may be passed, thus in effect producing a roller having a very small degree of elasticity, or none at all, depending upon the manner of locking, but still being superior to a rigid surfaced roller.

While I have described my roller as particularly applicable to the construction of road beds, it is obvious that it may be used to equal advantageon large foundations or for the construction orlaying-down of any area reouiring a smooth and evenlysupported surface; kIt is also obvious that my roller may be used to equal advantage on any nerfectly smooth road which is up to full supporting strength in all parts, in which case, it will finish a perfectly smooth surface, and as a further improvement I have provided means for adjusting the weighted members to vary the pressure which any one or more will occasion upon an insuiciently supported road surface and also means whereby thel able for working the surface on levees, em-

'Y bankments and tillable land, and I wish to be understood as claiming it for all such purposes. y Y

I claim z- 1.V In a road roller, a plurality of pressure members independently operating during the process of rolling, said members having a freedom of movement in a vertical direction but constrained to move substantially together in a horizontal direction, means for varying the degreeof pressure exerted by the pressure members.

2. In a road roller, a plurality of pressure members independently operating during the process of rolling, said members having a freedom of movement in a vertical direction but constrained to move substantially! together in a horizontal direction, andy means for locking said members against relative movement .between them.

4. In a road roller, a plurality of pressure membersindependently operating during the process of rolling, said members having a freedom of movement ina vertical direction but constrained to move substantially together in a horizontal direction, and

means for elastically locking said members t against relative movement between them.

5. In a road roller, a shaft, a roller member on each end`of said shaft and constrained to rotate concentric therewith, a plurality of pressure members between said roller members having freedom of vertical movement so as to establish substantially an equal pressure over the entire line of contact with the surface being rolled.

6. In a road roller, a roller shaft, a roller member 0n each end of said shaft, a plurality of pressure members between said roller members establishing substantially an equal pressure over the entire line of contact with the surface being rolled, in combination with adjustable means fo1-\-a1ying the pressure set up by the pressure members. f

7. In a road roller, a shaft, a roller member on each end of-said shaft constrained to move concentric therewith, a plurality of pre sure members between said roller membex establishing substantially an equal pressure over the entire line of contact with the surface being` rolled, in combination vwith means for driving s'aid roller members.

JOHN H. HENDERSON. 

